Compound suitable for tanning.



UTTQ SCHMIDT ANT) ARTHUR BHINE, GERMANY, CORPORATION.

cottro'onn' snrrennn non TANNING.

Specification of Letters Patent.

" see an nation.

' u RES, or LUDWIGSHAJFEN-ON-THE-RHINE, ennmen'm ASSIGNORS T nanrsonn ANILIN & sore remain, on .LUnwIGsHArnN-on-Tnn' no Drawing. Application filed March 23, 1914. Serial No. 826,610.

To all whom it'may'concem: .l

' Be it known that we, Oi'ro SCHMIDT and ARTHUR ANDRES, citizens of the German Empire, residing at Ludwigshafen-on-the- Rhine, Germany, have invented new and useful Improvements in Compounds Suitable for Tanning, of which the following is a specification.

We have discovered that we can repare a new class of sulfonated compounds ycausing a phenolic body containing not more than one hydroxyl grou in each nucleus, sulfuric acid. and an alde yde containing at least two carbon atoms, to react on one another in such a manner that the product contains at least one sulfonic acid group in themolecule. The order in which the initial materials are brought together is immaterial for the purposes of this invention. For'instance, the three compounds may be directly mixed together, or the phenol andthe aldehyde may first react upon one another, and

the product be treated with sulfuric acid,

but we do not restrict our invention to these specifically mentioned methods. For the purposes of this invention, a compound which gives rise to an aldehyde containing at least two carbon atoms, is regarded as equivalent to such aldehyde. Our new compounds, in the form of their free acids, are characterized by possessing a non-crystalline structure, they are readily soluble in water, yielding almost colorless solutions which become deeply colored on the addition of a ferric salt, and they tan hides, giving a useful leather. They contain at least two aromatic residues joined together by a residue containing at least two carbon atoms.

The following example will serve to illustrate how this'invention may be performed, but the invention is not confined to this example. Theparts are by weight. Example: Shake together for some time, 94 parts of phenol, 22 parts of pa-raldehyde, and a small quantity of concentrated sulfuric acid. As reaction takes place heat is "evolved, and care should be taken that the With water until a solution of 25* Baum is obtained. Then add ten grams of common salt to each literof this solution and employ it for tanning. Leather is obtained which, after being treated with fat, possesses a good resistance to tearing.

Now What we claim is v 1. The process of producing Water-soluble materlal suitable for use in tanning which consists in causing aphenolic body containingnot more than one hydroxyl group in each nucleus, sulfuric acid and an aldehyde containing at least two carbon atoms, to react on one another in such a manner that the product contains at least one sulfonic acid group in the molecule.

2. The process of producing water-soluble material suitable for use in tanning by condensing together phenol, paraldehyde and sulfuric acid in such a manner that the product contains at least one sulfonic, acid group in the molecule.

3. As new articles of manufacture, sulfonated condensation products of a phenolic body containing not more than one phenolic hydroxyl group in each nucleus, with sulfuric acid and an aldehyde containing at least two carbon atoms, which new compounds are light colored non-crystalline bodies containing sulfur, which are soluble- 1 carbon atoms.

l 'As new articles of manufacture, the sulfonated condensation product from phenol, and paraldehyde, which product is a light colored amorphous body, containing sulfur, is soluble in Water yielding an almost lPatented Jan. 22, rate.

colorless solution, which becomes deeply colset our hands in the presence of two subored on the addition of a solution of a ferric scribing witnesses.

salt, which tans hides, giving a useful OTTO SCHMIDT.

leather, and which contains at least two ARTHUR ANDRES. 5 phenolic residues joined together by an ace- Witnesses: e

taldehyde residue. J. ALEc LLOYD,

' In testimony whereof we have hereunto S. S. BERGER- 

